Notes from the parser.

Walk through a real .prompt file block by block. What each piece means, why it exists, and what the AST looks like when the parser is done with it.

A provider abstraction is not about hedging your bets. It is about keeping the prompt as the unit of work — and making the SDK the implementation detail it should always have been.

F-strings work until they don't. Once a prompt has params, defaults, techniques, and provider constraints, it stops being a string and starts being a program. Give it a grammar.